pub fn odd_fibnacci_sum(threshold: u32) -> u32 {
    let mut a: u32 = 1;
    let mut b: u32 = 1;
    let mut sum: u32 = 1;
    while b <= threshold {
        if b % 2 == 1{
            sum += b;
        }
        let tmp = b;
        b += a;
        a = tmp;
    }
    sum
}
